As various nonionic surfactants and anionic surfactants which are generally used at present, those derived from alcohols originated from petrochemical raw materials or alcohols originated from oil and fats raw materials are known.
As the method of producing alcohols originated from petrochemical raw materials which alcohols are called synthetic alcohols, for example, there is a method in which a compound having an internal olefin is derived by an oligomerization reaction through ethylene and then converted into an alcohol derivative by oxo reaction. It is known that the synthetic alcohol obtained resultantly is a mixture containing about 20% by weight of branched alcohols besides about 80% by weight of linear alcohols. It is known that various nonionic surfactants and anionic surfactants derived from synthetic alcohols have such excellent characteristics that they are superior in low-temperature stability because they have a lower melting point and low coagulation point than derivatives from linear alcohols.
On the other hand, it is known that various nonionic surfactants and anionic surfactants derived from alcohols originated from oil and fats raw materials which alcohols are one type of natural alcohols have the characteristics such as high foaming ability, low cmc, high cloud point and high emulsifying ability.
As mentioned above, the surfactants derived from synthetic alcohols are different from those derived from natural type alcohols in properties and performances. Therefore, it is usually necessary to use different surfactants according to the use of the surfactant at present.
There is an increased and worldwide demand for natural alcohols in view of the carbon neutral at present. However, surfactants derived from natural alcohols have the drawbacks that they are inferior to those derived from synthetic alcohols in low temperature stability. Therefore, there is a fear that they have not a little adverse influence on the appearance and performance of a system in which they are blended.
If natural alcohols or their derivatives can impart the same characteristics and performances as synthetic alcohols or their derivatives without losing their excellent characteristics and performances, the use of an alcohol in accordance to the state of affairs of raw materials is largely expected regardless of the purpose and use. Therefore, there is currently a strong desire to develop technologies for reforming the properties of natural alcohols and their derivatives.
Examples of major alcohol type anionic surfactants include alkyl sulfates (AS) and alkyl ether sulfates (AES). These surfactants are widely used not only for domestic uses such as dish detergents, shampoos, body detergents, clothing detergents and house detergents but also for chemical uses such as emulsion polymerization emulsifiers and dyeing adjuvants. These surfactants are usually formulated in a concentration as low as about 20% by weight or less in product formulation systems. However, an aqueous AS or AES solution has a low viscosity in this concentration range and it is necessary to adjust the aqueous solution so that the solution has a proper viscosity corresponding to its use (JP-A55-84399, JP-A 56-72092). Accordingly, various thickeners have been investigated so far.
Currently, as the thickeners for various chemical products, fatty acid alkanolamides, such as fatty acid monoethanolamides (JP-A61-114727), fatty acid diglycol amides and fatty acid diethanolamides, reduced irritation to the skin or hairs are preferably used.